Colony counting apparatus for laboratory use



Oct. 27, 1931. T. c. BUCK, JR 1,829,472

COLONY COUNTING APPARATUS FOR LABORATORY USE Filed Feb. 23, 1 3 Sheets-Sheet 1 INVENTOR.

warms. (sum/ 4, BY 7 A TTORNEY.

T. c. BUCK, JR 1,829,472

COLONY COUNTING APPARATUS FOR LABORATORY USE Filei Feb. 23. 1927 a Sheets-Sheet 2 r \4 I l :5 IN VEN TOR.

Uct. 27, 1931. T. c. BUCK, JR

COLONY COUNTING APPARATUS FOR LABORATORY USE Filed Feb. 25, 1927 5 Sheets-Sheet I5 I N VEN TOR.

A TTORNE Y.

Patented Get. 27, 1931 UNHTED STATES THEODORE C. BUCK, 31%., OF BALTIMORE, MARYLAND COLONY COUNTING APPARATUS FOR LABORATORY USE Application filed February 23, 1927. Serial N'o. 170,404.

This invention relates to improved colony counting apparatus for laboratory use for testing various substances, particularly foods and fluids.

Colony counting devices usually employ what are known as Jeffer plates which are ruled and laid off to form divisions so that the substance under test may more readily be subdivided and the testing more accurately conducted.

It is also common in using apparatus of this kind to employ what are known as Petri dishes of a transparent glass upon which the substance to be tested is placed and these dishes are placed over the Jeifer plates during'the testing operation.

The'purpose of my invention is to provide an apparatus for facilitating these colony counting tests by properly illuminating the Petri dishes and the Jeffer plate with respect to the magnifying elements through which the substances to be tested are viewed.

With these, and other objects in view, the invention is illustrated in the accompanying drawings, wherein,

r Fig. 1 shows the complete apparatus, on a small scale and in side elevation.

Fig. 2 illustrates the same on a larger scale and in top or plan view. Y

Fig. 3 shows the same in topview but with the cover and its magnifying elements --removed. I

Fig. 4 illustrates a vertical sectional detail through the device as viewed on the line 44 of Fig. 5.

Fig. 5 shows a central longitudinal section through the apparatus, and

Fig. 6 illustrates a vertical sectional detail on the line 66 of'Fig. 5.

Referring to the drawings, the numeral 10 designates a casing or housing with vertical side walls 11; vertical-frontand' rear walls 12 and 13 and a bottom 14.

On the interior of this casing and extending from one side wall to the other are a series of cross-wise reflector plates 15. These plates are arranged to varying angles and extend from the said front wall all the way to and partly up at the rear wall as shown in Fig. 5 of the drawings.

The interior vertical surfaces of the side walls 11 are polished or otherwise treated to produce reflecting surfaces.

The two side walls 11 have side outputs 16 in their top edges and immediately below the edges of these cutouts each wall has a sup porting structure 17 along its inner side which in this instance has the form of a horizontal angle-plate.

The angle-plates on the inner sides of the 50 two opposite side walls are located i n the same horizontal plane so they may support a plurality of glass plates which will presently be explained.

Adjacent to the front wall 12, I provide 6, an inclined reflector plate 18 which extends upwardly above the front ends of the angleplates 17 and at the rear of the casing I provide a rearwardly and downwardly-inclined reflector-plate 19, whose lower rear edge 20 terminates adjacent to but spaced from a vertical reflector-plate 21, thus providing a space 22 between said plates 19 and 21 for a purpose that will also presently be explained.

Above the rear inclined reflector-plate 19. 1 I have the casing open at the upper edges of the side walls but I provide a curved or arched cover-plate 23 thereover, which latter however is open at opposite sides 24:. The purpose of this will also presently be explained.

At the rear end of the casing beneath the inclined reflector-plate 19 and the rear vertical refiector-plate 21, I provide a long horizontally-extending lamp 25 which projects from a socket located on the side wall 11. This electric lamp 25 has a pale blue glass as indicated by the horizontal shading in Fig. 4:, and when this lamp is burning, the heat generated thereby passes up through. the gap or 9 space 22 and escapes through the opposite side openings 24- of the arched cover-plate 23.

Between the blue lamp and the rear ends of the angle-plates 17, I locate a glass plate 26 which latter is supported in vertical brackets .9" 27 on the inner sides of each side wall. This glass plate 26 therefore has a vertical position in front of the lamp 25.

I have found in practice that best results are obtained if the vertical glass plate 26 isground and if the upper portion 28 thereof is vcolored a pale blue like the color of the lamp, and the lower portion 29 thereof is left plain but opaque as the result of the grinding.

outer end 32 of the rod. being shaped to .en-v

able it to be readily engaged by theflngers and turned more or less in either direction whereby to give the proper inclination to the reflector-plate to produce the best results.

main in the adjusted position. V The position-of the pivoted reflector-plate 30' is such that it maybe swung to assume practically a verticalposition so as to be in terposed between the lamp 25'and the upper blue portion 28 of the vertical glass plate26. r

j On th'eh'orizontal anglepla-tes17 I provide,"in this instance, three glass plates 33, 34 and 35 respectively. The lowermost glass plate'33; as indicated in Fig. 5, is'blue glassflth'e uppermost glass --plate 35, is plain plate glass while the interposed glass plate 34is plainbntghas a seriesof concentric circles 36, that are intersectedby a series of diametric lines 37', whereby to' form *aplu-rality of spaces or divisions 38''. j "The lined plate 34, isn'ot in itself newwi'th 'n'ie and'is well-known asJefier plate, but so a I far as I am 'aware'no one has'used'a J'efle'r plate. as I do in the present apparatus endin 'combination with the other plates.

' I The Jeffer plate is interposed betweeii'the upper plain glass plate 35 and thelower blue plate 33, but lines and-divisions on such {letter clear .p-lat'e.

plate may readily be seen through the upper Attention is directed to the' fact the horizontal axis of the lamp 26 is substantially in the same plane as the horizontal interposed Jefier plate 34 and that the blue colored portion 28 of the vertical glass Ip'la'te'l 26 extends up above the Jeffer plate and to the upper most {horizontal surface of the bliie lamp.

The object in this is'tointerce'pt direct light from the lamp to'the glass plates 33, 34; 35.

- The substance to be tested is contained'on a Petri dish 36 whichis inserted throughoneof the cut-outs or side openings 1 6" and laid on t'opof the uppermost plain glass-plate This dish36is of plain' glass so that when looking down from above, with the casing illuminated from 'beneath the .blue glass 33,

the division .lines' on the 'Llefiierplate 34, may be readily seen through Petri dish and the upper plain glass'35 and the collonies ion the dish over anyone orimorefof'the 'J'efler plate subdivision may be distin'guished'irom 5 those over other s-ub divis'ionsfi -I-provide the case with a coveri37' which top plain glass plate '35.

the topgl'ass plate 35, vertical colored glass V -none 'oftheplates33 f34 or 35 will besubhas position directly over the glass plates 33,

34 and 35 and this coverhas a depending the cover. The purpose of the flared flange is to cut off directlight. rays from the lamp "up into the tube and the underside of the The rod and reflector are so mountedas to re-,

cover and the surfaces of the flange and tube are all black to prevent reflections of light.

In thep-resent instance, I provide vertical "slots '41, ;in 'diametrically-opposite sides of the tube 39 and the slot atone side has oilsets or notches 42' at one side edge while the slot at the opposite side. has ofi-sets or notches 43 at the opposite side edge, as indi- "ca'td by full and broken lines in Fig. 1 of the "drawings;

5 Inthe tub'e39, I provide a c'ollarior ring 44 in which is mounted a magnifying lens 45 and handles 46; at opposite sides of the ring project through the slots 41, whereby the horizontal positionfof the... lens in the tube may be vari'ed by raising or lowering the "same in the tube. r

1 The handles 46 have reduced sockets 47 at lens in'jthe desired a'djus'ted position in the tube. v y e The uppererid=of the tube 39, ca rries a "head' piece 48, which has an opening whose marginal edge 49, is shaped'to' fitthe face. and

forehead-of anobserverduring the testing operation.

The lamp" 25, is sustained from socket 5O on'one of the side walls 11 and-electric curto this socket in th usual way.' Y In operation, the substanceto be tested'is lp'la'cedf on' the Petri' dish in the usual way and the dishis then moved through the'side cut-out 16in theside wall and seated on the I The lamp 25 being illuminated produces the light, and this light is reflected by the plates 21 and 15 against the under, side of the lowermost colored glass 'plate 33, so as touniformlylight that plate.

l 'Whe'n vi'ewedirom-above, the colored plate produces a dark background beneaththe Jeffe'r plate '34 and the lines on'jthe latter stand out very prominently.

3 Light-from the lamp to the upper side of isintercepted by the plate 26-28'so that jectto direct light from'the "lamp.

l-lO

" 'l he inclined reflector plate 18 at the front is so arranged that light from the rear end is reflected back so that there is practically a uniformity of light over the top plate 35.

The adjustable reflector plate 30 directs the light across the Petri dish from one side and causes slight shadows to be produced at one side of the colonies and renders the latter more perceptible.

The adjustable reflector 30 may also be operated to cut 011 light from above and thus permit only reflected light beneath the glass plates.

The lower plate 33 while in most instance is blue in color, may be of other colors, particle larly when the substance being tested has colored organisms therein.

It has been found in practice that the structure herein set forth and illustrated produces transmitted light to illuminate the substances on the Petri dish and reflected light to illuminate the colonies so that the colonies can be readily distinguished without eyestrains.

Having described my invention, I claim,-

1. In a colony counting device the combination with a casing, of a transparent ruled plate having divisions thereon and supported in the case so that external light shall be excluded from the under side thereof and so the substance to be tested may be sustained above said divisions, illuminating means enclosed in the case beyond the end of the ruled plate and a translucent plate between the end of the ruled plate and the illuminating means and extending at an angle with respect to said ruled plate said translucent plate having its upper portion colored and its lower portion white.

2. In a colony counter the combination with a casing, of a transparent plate having lines thereon to produce a series of divisions said transparent plate being arranged in the case so that external light shall be excluded from the under side thereof and so the substance to be tested may be carried above said lines, a colored translucent plate beneath the lined plate, an illuminating means in the easing and means for directing reflected light from the illuminating means against the under side of the colored translucent plate.

3. In a colony counter the combination with a casing, of a transparent plate having lines thereon to produce a series of divisions said transparent plate being arranged in the case so that external light shall be excluded from the under side thereof and so the substance to be tested may be carried above said lines, a translucent plate in the casing beneath the lined plate, an illuminating means also in the casing, means in the casing for directing reflected light from the illuminating means against the under side of the translucent plate and means also in the casing for directing light from the illuminating means across the case above the lined plate.

4. In a colony counting apparatus the combination with a casing, of a translucent plat-e supported in the casing, a ruled transparent plate also in the casing above the translucent plate, a plain transparent plate in the casing above the ruled plate, reflector devices in the casin and arranged at angles with respect to and beneath the translucent plate and illuminating means in the casing to provide light to be directed by the reflector devices against the underside of the translucent plate.

5. In a colony counting apparatus the combination with a casing, of a colored translucent plate supported in said casing, a ruled transparent plate in the casing above the colored translucent plate, reflector devices arranged in the casing at angles with respect to and beneath the colored translucent plate, a structure above the ruled transparent plate and said structure carrying a magnify in lens directly over the ruled plate and illuminating means in the casin 6. In a colony counting apparatus the combination with a casing, of a plate having lines thereonto produce divisions on the plate said plate being arranged in the casing so the substance to be tested may be located over said divisions, illuminating means in the casing and a movable plate in the casing above the lined plate and located between the illuminating means therein and the lined plate also therein said movable plate being arranged to direct the light projected from the illuminating means over the said lined plate.

7. In a colony counter the combination with a casing, of a plate sustained in the casing in spaced relation beneath the upper side of the casing on which the substance to be tested may be placed and also enclosed in the casing so that external light may be excluded from both the plate and the substance under test, means forming an enclosed passage to exclude external light said means extending from the interior of the casing over the said plate on which the substance to be tested is placed, to the outer upper side of the casing, a magnifying means in the said enclosed passage and illuminating means in the case.

8. In a colony counter the combination with a casing of a plate sustained in the casing in spaced relation beneath the upper side of the casing on which the substance to be tested may be placed and also enclosed in the casing so that external light may be excluded from both the plate and the substance under test, means forming an enclosed passage to exclude external light said means extending from the interior of the casing over the said plate on which the substance to be tested is placed, to the outer upper side of the casing, a magnifying means in the said enclosed passage, illuminating means in the casing to illuminate the under side 1' v of the said plate and thesubstance'thereon and means forcontrolling the passage of light from the interior illuminating means tothe upperside of said plate, below the top of the casing. 9. In a colony counting device the combination, with a casing closed to exclude ex.-

ternal light and" having. a sight opening at 1 its upper side,vof a transparent plate supported in the closed easing beneath the sighti openingandonwhich the substance to be testedmay be supported, magnifying means "f above the transparent plate, illuminating means in the-easing and adjustable reflector means also in the closed casing between the illuminating means and the'plate to regulate the light directed about the plate.

5 10., In a colony counting device the combination with a casing closed to excludeexternal light and having a sightopening at its upper side, of a transparent plate supported in the closed casing beneath the sight- I 5 opening and on which the substance to be tested maybe supported, magnifying means above the transparent plate, illuminating means in the closed casing, reflector means in the casing above and below said plate 5 and between the-illuminating means and the plate and said upper reflector means being I i v 1 adjustable to vary the rays ofjli ht about *theplate. In testimony'whereof I aifix my signature.

1: THEODORE LB oK, JR.

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